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Re: Resource-Type Revisited (httpRange-14)

From: Mikael Nilsson <mikael@nilsson.name>
Date: Mon, 07 Jan 2008 15:13:00 +0100
To: "Sean B. Palmer" <sean@miscoranda.com>
Cc: www-tag@w3.org
Message-Id: <1199715180.4783.15.camel@daneel>

Comments below:

On fre, 2008-01-04 at 15:30 +0000, Sean B. Palmer wrote:
> 
> So I figured that this would be okay:
> 
> [ :from "http://www4.wiwiss.fu-berlin.de/dblp/resource/person/100007";
>   dc:title "Journals TimBL has Contributed To" ] .

So your :from property means "whatever IR is returned by following the
redirect(s)". But this is not well-defined in the presence of
conditional redirects. Depending on the request, a server may
legitimately 303-redirect to completely different IRs. The semantics of
303 is so weak that this is not meaningful.

Second - what stops you from introducing this property if *you* find it
useful? It seems we're mixing two issues here: how do I as a developer
solve some of my pressing practical issues, vs. how should be specify
these things in the formal documentation? The :from property seems to
fall in the first category.  


> InformationResource: no
> 
> That'd be the simplest thing to do. But I think that it's nice to have
> a minimal amount of documentation, and if we're saying that this
> strange thing in HTTP space isn't an information resource, we might as
> well at the very least tell people what it is. Yeah it's a bit
> redundant, but I think it's really handy as a header: HEAD is the way
> to do queries to find the *essential* properties of something, and
> type seems to be a rather essential property.

This leads me to a reformulation of my stance on the IR issue... I think
it's wholly inadequate to talk about resources being IRs or not. That's
not what we're after. We want to know the following property of the
returned message: is this message a "representation" or not of the
denoted resource?

So any HTTP header for solving the IR issue would need to describe this
aspect of the message, not of the resource. 

200 Ok says about the message: "This message contains a representation
of the resource denoted by the URI in the request".

"InformationResource: no" says something about the resource that we
don't really have any use for.

The Description-ID header changes the above interpretation of "200 Ok",
and moves that attribute of the message to the new header: if there is a
Description-ID, then the message is not a representation.

/Mikael 



> 
> I'd be happy with "InformationResource: no", too, having said that.
> Anything that lets me use a *single* 200 to give information about
> people and the moon and whatever is fine by me. As long as we have the
> :from property too, that's all we need to say stuff about the
> information resource.
> 
-- 
<mikael@nilsson.name>

Plus ça change, plus c'est la même chose
Received on Monday, 7 January 2008 14:12:42 UTC

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